I predict that in twenty years, not dissimilarly to German in a sense, most Japanese nouns will be written in katakana. Why? Because they'll all be English loanwords. I was in the grocery store, looking for some matcha; I didn't want the loose-leaf stuff because it's a pain in the ass to futz around with it in the office. Finally found an (expensive) little jar of the stuff with all the right characters and whatnot - but then in the ingredient list it said (in katakana) "instant tea".